1. Field of the Invention
The present invention relates to a finder visual field switching mechanism, and more particularly to a switching mechanism for a switching visual field frame, which is capable of switching a plurality of visual field patterns conforming to a print aspect ratio selected during the photographing.
2. Description of the Related Art
The conventional optical finder incorporated into a camera is constructed in such a manner that an objective lens, a prism, and an eyepiece are arranged in a finder unit body frame, and the subject light passing through the objective lens is bent by the prism and is led to the eyepiece so that the subject image can be observed through the eyepiece.
A visual field frame for controlling the range of the visual field is arranged on a light path of a finder optical system. There is known a visual field frame composed of a switching visual field frame provided with a visual field switching mechanism which can determine a visual field conforming to a print aspect ratio (PAR). For example, there is proposed a CHP switching visual field frame which is able to select one size among conventional (C), high-vision (H), and panoramic (P) for photographing, and switch the visual fields conforming to the PAR.
However, the conventional switching visual field frame ordinarily expands and contracts the range of the visual field by moving a pair of L-shaped visual field frame pieces arranged to face each other vertically in a direction so that they can become closer to each other or far from each other. The power for switching the visual fields is mechanically transmitted via gears and/or connecting members; therefore, a power transmitting mechanism is faced with a problem of being unsteady, and a visual field conforming to the PAR cannot be determined accurately.